This invention relates to tensioning devices for drum type percussion instruments and more particular to the use of tensioning rod support posts located at approximately the nodal point of the drum shell.
The art of manufacturing percussion instruments of the drum type dates back hundreds of years and some examples of drums with tensioning or tightening devices are shown in the following U.S. Pat. Nos.: 578,198; 635,856; 663,855; 794,658; 1,014,109; 1,042,806; 1,121,909; 1,443,191; 1,648,212; 2,132,105; 2,173,443. A review of these patents shows various types of tensioning rods with support posts extending from the periphery of the drum to engage and support the axially extending rods at one or more spaced locations along the length of each rod. In some cases, such as in U.S. Pat. Nos. 794,658 and 1,014,109, there is one post for each rod and it is located at the midpoint of the rod.
In other of these patents, such as U.S. Pat. Nos. 663,855 and 1,121,909, there are two posts for each rod and each is located an equal distance from the upper and lower edge of the drum shell.
Unlike the prior art construction, this invention utilizes at least one support post for each rod and the post is disposed at the vibratory nodal point of the drum shell which is at a distance of approximately one-fifth (1/5) the overall height of the drum shell measured from the adjacent edge of the drum. Where only one such support post is used, it is located at the vibratory nodal point adjacent the lower end of the drum.
The principal object of this invention is to provide an improved drum having constructional features which do not affect the harmonic vibrations of the drum shell caused by the striking of the batter head.